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Hugh Jackman as Logan/Wolverine in a scene from the film, "The Wolverine." The film opens July 25, 2013.

Updated at 12:10 AM EDT on Sunday, Jul 21, 2013

On the penultimate day of Comic-Con, discussions turned to finding the heart in scenarios which often feature creatures that may not even have one.

Balancing the dramatic tension, the human emotions that make you root for the protagonist in relation to the action sequences that more often than not are the box-office draw is perhaps the greatest challenge, and the greatest allure of fantasy entertainment.

"We have to ground everything in reality," Jim Kouf, executive producer and writer for the television series "Grimm," says. "If the rules are so loose, at some point you don't believe it and then you stop buying into the fantasy."

In "Grimm," David Giuntoli plays a homicide detective who discovers he is a descendant of hunters who fight supernatural forces and must face all manner of ancient evils and supernatural creatures including Reapers, Blutbaden and Hexenbiest.

It was that balancing act of keeping the humanity on par with the supernatural that initially drew actor Bree Turner to the role of Rosalee Calvert on the NBC series. "I think it's the whole point of the show, if you go to far in any direction you are going to lose the fans, the audience and the heart of the show," she said late Saturday afternoon in San Diego. "It's why I said yes to the show. I came in late in the first season and I had watched the show and there was this beautiful, really out there genre concept grounded by real relationships."

The approach rings true regardless of whether the property or franchise is a weekly series enjoyed in the comfort of your own home, or a summer blockbuster replete with dazzling special effects and jaw-dropping action sequences.

In 2014's "Dawn of the Planet of the Apes," the sequel to "Rise of the Planet of the Apes" (2011) and set ten years later, the humanized ape Caesar is struggling with issues most simians never encounter. And that's why audiences are invested not only in the story, says director Matt Reeves, but to the emotional journey of Caesar, regardless of his genetic makeup.

"It's all about the character," Reeves says, explaining that initially you are attracted to the property because they are apes. "But the key to the whole thing is what is going on underneath, what Andy [Serkis] does and what the other actors do when they are playing apes. ...The key to everything was the emotional reality of these characters - and so once you achieve that you forget about that they are apes."

"I'll never forget reading the script for the first time and seeing the trajectory of the character, the arc of the character and then realizing and it's an ape," Serkis said. "If you take that away it is still an amazing character going on a phenomenal journey. There was this creature that was going through all these recognizable human emotions like being an outsider or being rejected and then finding his people."

And that's why we, the audience, identify and often return again and again for sequels, prequels and spin-offs.

"What 'X-Men' did and Wolverine is a great example of it," explains Hugh Jackman, who returns to his beloved character in "The Wolverine" and also in 2014's "X-Men: Days of Future Past," "is to make superheroes human, complex, flawed, interesting. That's why so many diverse actors and great directors take them on. Because there is an opportunity for something very, very human as well as something spectacular."